首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1200篇
  免费   70篇
  国内免费   5篇
耳鼻咽喉   11篇
儿科学   23篇
妇产科学   19篇
基础医学   158篇
口腔科学   30篇
临床医学   92篇
内科学   293篇
皮肤病学   31篇
神经病学   123篇
特种医学   40篇
外科学   174篇
综合类   9篇
预防医学   86篇
眼科学   20篇
药学   74篇
中国医学   4篇
肿瘤学   88篇
  2023年   14篇
  2022年   11篇
  2021年   26篇
  2020年   28篇
  2019年   41篇
  2018年   47篇
  2017年   33篇
  2016年   25篇
  2015年   37篇
  2014年   59篇
  2013年   57篇
  2012年   90篇
  2011年   93篇
  2010年   63篇
  2009年   33篇
  2008年   58篇
  2007年   80篇
  2006年   67篇
  2005年   58篇
  2004年   62篇
  2003年   37篇
  2002年   44篇
  2001年   29篇
  2000年   36篇
  1999年   27篇
  1998年   10篇
  1997年   5篇
  1996年   3篇
  1995年   7篇
  1993年   2篇
  1992年   11篇
  1991年   15篇
  1990年   4篇
  1989年   12篇
  1988年   7篇
  1987年   5篇
  1986年   5篇
  1985年   2篇
  1984年   4篇
  1983年   4篇
  1981年   3篇
  1980年   2篇
  1978年   2篇
  1977年   2篇
  1972年   2篇
  1971年   1篇
  1970年   3篇
  1968年   3篇
  1959年   1篇
  1956年   1篇
排序方式: 共有1275条查询结果,搜索用时 16 毫秒
1.
2.
3.
4.

Objective  

The aim of the project was to assess the effectiveness and safety of weekly epoetin-beta (EB) in patients with gastrointestinal cancer (GIC) subjected to concomitant chemoradiotherapy (CCTRT).  相似文献   
5.
INTRODUCTION: Traditional advanced imaging modalities such as CT and MRI are limited in their ability to perform accurate linear distance and angular measurements regardless of anatomical orientation. The construction of 3D models has been used to perform anthropometric analyses as well as in the reconstruction of rapid prototypes. We hypothesized that such measurements would be precise to within 2 mm or 2 degrees of measurements performed with a coordinate measurement machine (CMM). We also hypothesized that there would be a high degree of interobserver reliability with these measurements. MATERIALS AND METHODS: Multiple aluminum screws were implanted in various positions in three foam pelvises which were subsequently scanned by CT and rendered as 3D models using a commercially available software package (Mimics). Linear and angular measurements were performed using a CMM machine, the software package, and a dial caliper or goniometer. The deviation of the measurements from the CMM data was compared using ANOVA. The interobserver reliability of both the manual and computer-generated measurements was calculated. RESULTS: The mean difference between the CMM distances and those measured manually and with the software was 2.12 +/- 1.20 mm and 1.57 +/- 1.05 mm, respectively. The mean difference between the CMM angular measurements and the angular measurements performed manually and with the software was 4.07 +/- 4.70 degrees and 1.62 +/- 1.32 degrees, respectively. In all cases, the manual measurements were significantly less accurate (p < 0.0001) and there was a high degree of interobserver reliability. CONCLUSIONS: Computer-generated measurements taken from three-dimensionally reconstructed models are more accurate than manual measurements and are within 2 mm and 2 degrees of measurements performed with a CMM. These measurements have high interobserver reliability.  相似文献   
6.
7.
The Monte Carlo method was used to calculate the efficiency, escape and Compton curves of a planar high-purity germanium detector (HPGe) in the 20-150 keV energy. These curves were used for the determination of photons spectra produced by an X-ray machine in order to allow a precise characterization of photon beams applied to medical diagnosis. The detector was modeled with the MCNP5 computer code and validated by comparison with experimental data. The air kerma calculated after the spectra stripping was compared with ionization chamber measurements.  相似文献   
8.
Venous leg ulcers derived from tissue destruction is the consequence of a chronic inflammatory process that produces pain and physical disability, diminishing quality of life in patients. In this work, Lassar ointment and lyophilized collagen‐polyvinylpyrrolidone were administered separated each on one half in the same ulcer to 9 patients at the beginning and every 4 days. On day 16, all patients were auto‐grafted with partial thickness skin. Granulation tissue and graft integration were assessed clinically during 3 months. Inflammatory infiltrate, type I and III collagens, elastic fibers, alkaline phosphatase as well as blood vessels were evaluated histologically or histochemically in biopsies taken at the beginning and 16 days after the local treatment. Clinically and morphologically, both treatments demonstrated appropriate granulation tissue promotion and optimal graft integration since the beginning. Nevertheless, in Lassar ointment treated group regionalization of alkaline phosphatase activity was observed, as well as the presence of granuloma in 2 of the 9 patients. In conclusion, Lassar ointment or lyophilized collagen‐polyvinylpyrrolidone are two different promoters of granulation tissue in venous leg ulcers, however Lassar ointment has the capability to produce granuloma and an exacerbated immune response; in consequence, ulcer recidivism could be present, may be due to mineral deposits in the wound.  相似文献   
9.
10.
A wide range of vascular disorders can affect the spleen. Although clinical presentation is often nonspecific, early diagnosis and treatment are mandatory in most conditions. Noninvasive imaging techniques are well suited to meet these objectives. Familiarity with normal macroscopic and microscopic vascular anatomy is a prerequisite to understand the pathophysiology of vascular disorders of the spleen. This article deals with diseases of the splenic vasculature (aneurysms, arteriovenous fistula, splenic vein thrombosis, collateral circulation in portal hypertension) as well as vascular disorders affecting the splenic parenchyma (splenic infarct, Gamna-Gandy bodies). Primary vascular tumors and tumor-like conditions of the spleen will be discussed very briefly.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号